Process for finishing dyeings



3,086,832 PROCESS FOR FINISHING DYEENGS Richard Casty, Basel,Switzerland, assignor to Ciba (Iorporation, a corporation of Delaware NoDrawing. Filed Mar. 13, 1959, Ser. No. 799,088 Claims priority,application Switzerland Mar. 21, 1958 Claims. (Cl. 8-54) It is knownthat cellulose fibers, such as cotton, can be dyed with advantage withdyestuffs which contain mobile reactive halogen atoms. It is also knownthat nitrogenous fibers, especially wool, can be dyed with the aforesaiddyestuffs in acid baths. However, the aforesaid dyestufis are onlypartially suitable for this purpose. Some of these dyestuflfs yielduseful wool dyeings only in conjunction with certain assistants, whichare hereinafter described. Generally, these dyestuffs have thedisadvantage that they yield wool dyeings having unsatisfactoryproperties of wet fastness when the dyeing is carried out in the usualmanner from an acid bath with or without one of the aforesaid additions.The properties of Wet fastness, for example, the fastness to washing orperspiration, leave something to be desired not so much with respect tochange in tint as with respect to bleeding on to or soiling fibrousmaterials that are undyed or differently dyed. This invention provides aprocess which enables this disadvantage to be largely or completelyovercome.

Thus, the invention is based on the observation that by raising thepH-value of the acid dyebath after the dyestufi has been absorbed by thefiber the properties of wet fastness in relation to bleeding can be verysubstantially improved. Accordingly, this invention provides a processfor finishing dyeings which have been produced on nitrogenous fiberswith dyestuffs which contain at least one mobile halogen atom, in acidbaths, wherein, after the fibers have absorbed the desired quantity ofdyestutf, the pH-value of the dyebath is raised above 6.

The process is applicable -to any nitrogenous fibers that have been dyedin the aforesaid manner, for example, silk or fibers of a polyarnideobtained from e-caprolactam or from adipic acid and hexamethylenediamine. However, the process is especially advantageous for W001dyeings.

The dyestuffs with which the fibers are dyed must contain at least onemobile halogen atom, that is to say a halogen atom capable of reactingwith the fibrous material, for example, a bromine atom or advantageouslya chlorine atom. In other respects the dyestulfs may belong to a verywide variety of classes of dyestuffs, for example, there may bementioned stilbene dyestufifs, nitrodyestuffs, triphenylmethanedyestuffs, water-soluble phthalocyanine dyestuffs and above all acidanthraquinone or azo-dyestufis, including metal-free and metallizable ormetalliferous monoor poly-azo-dyestutl's. In order that they can be dyedfrom acid baths, the dyestulfs must be soluble in such baths andtherefore usually contain at least one sulfonic acid group.

The mobile halogen atom may be bound, for example, to the acyl radicalof an acid containing at least one acid group of the constitution JLOHfor example, to an acyl radical of cyanuric acid or of an aliphaticcarboxylic acid. In the case of the acyl aent 3,086,832 Patented Apr.23, 1963 in which X represents an alkyl, aryl, aralkyl, alkylmercapto orarylmercapto group, or more especially an amino group which may besubstituted or a hydroxyl group which is advantageously substituted; ora dichlorotriazine radical.

The halogen-containing acyl radicals of aliphatic carboxylic acidsadvantageously contain few carbon atoms, for example, two or threecarbon atoms. As examples there may be mentioned the chloracetyl group,the ocor fi-chloropropionyl group and above all the aIB-diClIllOIO-propionyl group.

A large number of such dyestuffs is known or can be made by methods inthemselves known, for example, from dyestuff components which containthe mobile halogen atoms, or by introducing by methods in themselvesknown radicals which contain mobile halogen atoms. Thus, by reacting anazo-dyestufr' or anthraquinone dyestuff which contains a reactivehydroxy, mercapto or preferably a free amino group with chloracetylchloride, ,8bromoor fl-c'hloro-propionyl chloride, chloropropionicanhydride or azfl-dichloropropionie acid chloride or anhydride, cyanuricchloride or a primary condensation product of cyanuric chloride whichcontains two chlorine atoms and, instead of the third chlorine atom, afree amino group or an organic radical, there are obtained valuablecondensation products, which contain a mobile chlorine or bromine atomand are suitable for use in the process of this invention As statedabove, some of these dyestuffs, especially those containing three ormore than three sulfonic acid groups, when used for dyeing wool fromacid baths yield weak, unlevel (skippery), practically useless dyeings.However, valuable level dyeings are produced with the aforesaiddyestuffs by dyeing wool in an aqueous bath in the presence of acompound which contains at least one basic nitrogen atom, to which isbound at least one radical containing a polyglycol ether chain, and themolecule contains at least three l I groups (advantageously --CH -CH Ogroups) and at least four carbon atoms that do not belong to such agroup. In finishing dyeings by the process of this invention it istherefore of advantage, when these disadvantageous dyestuffs are usedfor dyeing, to add a nitrogen compound of the above constitution.

'Ihe-se nitrogen compounds apart from the fact that they must possessthe characteristics defined above, may have a wide variety ofconstitutions. It will sufiice herein to mention, as compoundsespecially suitable for this purpose, nitrogen compounds of the formulaHr-CHr-mrd in which R represents an advantageously unbranched aliphatichydrocarbon radical containing at least 12 and preferably 16-20, carbonatoms, m and n each represents the whole number 1 or 2, and p, q and reach represents a whole number and the sum of p+q+(m-1)(r-1) is at least3, for example, 6 to 16.

Instead of the compounds containing free hydroxyalkyl groups, there maybe used as assistants in the present process esters of thesehydroxyalkyl-compounds with polybasic acids, for example,phosphoricacid'or sulfuric acid, or water-soluble salts of these acids,for example, alkali metal saltsor saltswith ammonia or amines.Furthermore, in some cases skippery dyeings can be avoided by adding tothe dyebath a cation-active compound, for example,cetyltrimethylammonium bromide, and also advantageously a polyglycolether of an aliphatic alcohol of high molecular weight.

The dyeings with which the present process is concerned are dyeings thathave been produced in acid baths, and for-this purpose the dyeing isadvantageously carried out in an acetic acid medium, that is to say, thedyebath has an acetic acid reaction at least at the beginning of thedyeing operation. It is therefore of advantage to incorporate in thedyebath advantageously at the beginning of the dyeing operation at leastsufficient acetieacid to produce the desired pH-value, account beingtaken of the fact that both the fibrous metal and the dyestuif which isusually present in. the form of an alkali metal salt consume a certainamount of acid. In general it is of advantage to add sodium sulfate tothe dyebath.

' As is usual in dyeing nitrogenous fibers, especially wool, the dyeingis carried out'ata raised temperature, advantageously by commencing thedyeing process proper at about 50 C. to 80 C., and then heating thedyebath to the boiling temperature and continuing the process andcompleting itat that temperature. However, it has been found that indyeing wool by the process of this invention it is not necessary to workatthe boiling temperature of the dyebath or very close to thattemperature. Usually equally good results are obtained by carryingoutthe dyeing process at a temperature distinctly below the boilingtemperature, for example, at a temperature within the rangeof 80 C. to90 C. When the dyeing is carried out in the presence of one of theaforesaid nitrogenous compounds, it is of advantage to enter thegoods'into the bath, which contains the acid andthe assistant, that isto say the nitrogenous compound, and-if desired sodihmsulfate, at roomtemperature or at most a moderately raised temperature, then to raisethe temperature of the bath and when the bath is hot, for example, at 50C; to 80 C., to add the dyestufiin the form ofan aqueous solution. Ifdesired, the dyeing may be carried out in a suitable apparatus at atemperature above 100 C., at about 107 C.

The pH-value of the bath is then raised above 6. In order to raise thepH-value of the bath almost any watersoluble compound of alkalinereaction can be used.

11 -0 O-NH However, in order to avoiddamagingthe fibers, especially inthe case of wooldyeings, it is of advantage; to add a compound ofalkaline reaction of which. an excesscan be added without raisingv thepH value higher than about 9, and advantageously the pH is-raised to avalue within therange of 6.5 to 8.5. For this purpose it is of advantageto use nitrogenous bases, for example, amines such as ethanolamines. -Insome cases ammonia is quite suitable, and especially suitable ishexamethylene tetramine.

Alkali metal ortho-phosphates or polyphosphates or bicarbonates are alsoof advantage.

Only a relatively short time is required for the treatment at the higherpH value, for example, about 10-30 minutes. It is preferably carried outat about the same temperature as that at which dyeing was carried out.For example, the dyebath may be maintained at the boiling temperatureduring the after-treatment, or the temperature may be allowed to fallslightly, for example, by discontinuing the supply of heat after thepH-value has been raised. Finally, the dyeings can be rinsed in theusual manner with warm and/ or cold water and dried.

When dyeing is carried out in an acid bath in the presence of anitrogenous compound of the kind referred to above, a considerableamount of the nitrogen compound remains adhering to the wool afterrinsing and drying. This may cause a change in the feel of the wool, achange in the behaviour of wool piece goods in. after-dressingtreatments, or, due to the increased slip. of the material, may alfectthe spinning properties of loose, wool or combed wool, and a change inthe speed of drying of the wet wool is frequently observed. Theseusually undesirable phenomena are avoided by raising the pH-valuebecause the nitrogenous compounds are retained. by thewool only underacid conditions, whereas they remain in solution in neutral baths orreturn to the dyebathwhen the wool surface is neutralized.

The process of this invention is especially suitable for dyeing mixturesof nitrogenous fibers with cellulose fibers, for example, so-calledhalf-wool, since it can. be carried out in a 2-stage process in a singlebath. The wool com:-

ponent of themixed fibers is first dyed in the manner described above,the cellulosic component remaining sub.- stantially undyed. Afterraising the pH-value, for example, by means of ammonia, there are added,advantageously without the further supply of heat, first sodium sulfateand then a direct-dyeing cotton dyestufi. It is. of

advantage to use a dyestuff which does not dye 'wool at all or only veryslightly in the vicinity of 100 C. The

dyeing is then continued until the cellulose fibers have attained thedesired tint, for example, for about /2 hour, and then the, dyeing isfinished in the usual manner. In order to improve the properties of wetfastness' of the dyed cellulosefibers it may be of advantage to subjectthem to an after-treatment in known manner with. an agent capable ofimproving the properties of wet fastness, for example, the condensationproduct of dicyandiamide and formaldehyde.

The following examples illustrate the invention, the parts being byweight:

Example 1 100-par-ts of knitting wool, 3000 parts of water, 10 parts ofcrystalline sodium sulfate, 6 parts of acetic acid of 40% strength and0.5 part of the addition compound from oleylamine and ethylene oxidedescribed below are heated'to C; A solution of 2 parts of the dyestufiof the formula.

SOIH

ness of this dyeing to wetting, more especially insofar as bleeding intocotton is concerned, is subsequent increase of the pH value. Before theaddition of hexamethylene- 6 tetramine the pH is about 4.8, and theaddition raises it to Instead of the dyestufi of the above formula theremay about 7.2. be used the dyestufl? of the formula The additioncompound of ethylene oxide is prepared in the following manner:

100 parts of commercial oleylamine are mixed with 1 5 0-01 part offinely disintegrated sodium, the whole is heated to l N l 140 C. Whenthe ethylene oxide is being absorbed rapidly, the reaction temperatureis reduced to 120 to (Red) 125 C., and the introduction of ethyleneoxide is con- HO S- SO3H Cl tinued until 113 parts thereof have beenabsorbed. The

Eamon product obtamed m fins manner glves prac' Practically identicaldyeings are obtained when, after tically clear solution in water.

the addition of the dyestufi, the bath temperature 1s Instead of theabove ethylene oxide adduct the followraised only to 85 C. dyeing beingcontinued at this ing products may be used:

(a) N-alkyl-propylenediamine (whose alkyl radicals i ii g i th f the H 1correspond to the radical of tallow fatty acid)+8 mols us a 0 W1 l ma 6I .lsmg o p Va He towards the conclusion of the dyeing operation may beof g i fil gg g mols of ethylene oxide. achieved with triethanolamine orsodium bicarbonate.

(c) Dodecylamine+3 mols of propylene oxide (this Example 3 product canbe prepared thus: 24 parts of commercial dodecylamine are heated to 160in the presence of 0.13 part of finely disintegrated sodium in a currentof nitrogen. Gaseous propylene oxide is then introduced until 19.5 partsthereof have been absorbed); (a) O NH: (d) The acid sulfuric acid esterobtained as follows: 25 II I 79 parts of a mixture of fatty amines (0.3mol) con- SOSH sisting of of hexadecylamine, 25% of octadecylamine and45% of octadecenylamine are reacted with ethylene oxide in the presenceof 0.8 part of sodium until Dyebaths are prepared containing in 2000parts of water, 6 parts of acetic acid of 40% strength and 1 part eachof the dyestutfs of the formulae:

106 parts (2.4 mols) of ethylene oxide have been ab- 30 O (Blue) sorbed.ll 5 C1 The reaction temperature is at first 140 to 150 C. S033 and canbe gradually reduced to 120 to 125 C. 30.75 parts (0.05 mol) of theresulting ethylene oxide adduct (5) H2N are mixed in a stirring flask at60 C. within 15 minutes I with 5.4 parts of urea and then within 30minutes with ON=N 5.4 parts of sulfamic acid (0.05 mol+10%) and kept I Il I (Red) for 5 to 6 hours under nitrogen on a boiling water bath. H033H 7 The resulting product (41 parts) is readily soluble in wa- I ter andis of neutral reaction. 803B (I]N@SO3H (Yellow) HzC(l3HC-HNQN= O\ I O101 or 0 so H N Example 2 A piece of wool (100 parts) is immersed at 60C. in O a dyebath containing in 4000 parts of water 5 parts of I Hacetic acid of 40% strength, 10 parts of crystalline sog dium sulfate,0.25 part of the ethylene oxide adduct de- I scribed in the 2ndparagraph of Example 1 and 2 parts S0311 of the dyestufi of the formula(Red) At 60 C. parts of wool tops are immersed in the sioaH 17111 f kdyebath which is raised to the boil within /2 hour, and N N dyeing iscarried out at the boil for 1 hour. The heating TNT-N is thendiscontinued and 2.5 parts of trisodium phosphate I are added. After 15minutes, the wool is taken out of H038 $0311 01 the dyebath, rinsed anddried. The resulting dyeings have much better fastness to wetting thanwhen the sub- Th 1 6 whole 18 ralsed to the boll wlmm /2 hour and dyesequent addition of trisodium phosphate is omitted. This mg is P l on atthe boll for 1 hour The heanpg 1s addition raises the pH value of thedyebath from about then discontinued, and 3 parts of aqueous ammonia of47 to about 67 25% strength are added. After 15 minutes the wool is 7Exam le 4 removed from the dyebath, immediately rinsed in water p anddried. A level red dyeing is obtained having a tast- 100 parts of ablended yarn of equal parts of wool ness to wetting which is much betterthan when no amand regenerated cellulose (staple fibers) are immersedmonia is subsequently added. The addition of ammonia at 50 C. in adyebath containing in 4000 parts of water raises the pH value from about5.0 to 8.0. 7 5 parts of acetic acid of 50% strength, 0.5 part of the 7ethylene oxide adduct described in the 2nd paragraph of Example 1 and 1part of the dyestufi of the formula The whole is raised to the boilwithin /z hour and dyeing is continued for /2 hour at the boil. Theheating is then discontinued, and 3.5 parts of aqueous ammonia of 25%strength, 30 parts of crystalline sodium sulfate and 1.5 parts of thedyestutf of the formula SiO 311 H (I) are, added. The temperature isallowed to drop to about 80 C. within /2 hour. The dyeing is rinsed incold water and dried. A very level, pure red dyeing is obtained.

To improve the wet fastness properties of its cellulose fibers, thematerial dyed in this manner can be aftertreated in known manner with acondensation product from 2 mols of formaldehyde and 1 mol of thereaction product from 1 mol of ethylenediamine dihydrochloride with 2mols of dicyandiarnide.

What is claimed is:

1. A process for finishing a dyeing produced on nitrogenous fibers in anacid bath with a dyestufi' containing at least one mobile halogen atom,which comprises raising the pH value of the bath above 6 when the fibershave absorbed the desired quantity of dyestuff.

2. A process for finishing a dyeing produced .onwool in an acid bathwith a dyestuff containing at least one mobile halogen atom, whichcomprises raising the pH value of the bath above 6 when the fibers haveabsorbed the desired quantity of dyestuft.

3. A process for finishing a dyeing produced on wool with a dyestutfselected from the group consisting of a dyestufi containing achloropropionyl radical and a dyestufi containing a chlorotriazineradical in a bath which is acid with acetic acid at the beginning of thedyeing operation, which process comprises raising the pH value of thebath above 6 when the fibers have absorbed the desired quantity ofdyestufl.

4. A process for finishing a dyeing with a dyestufi containing achlorotriazine radical in a bath which is acid with acetic acid at thebeginning of the dyeing operation, which process comprises raising thepH value of the bath above 6 by additon of a nitrogenous base when thefibers have absorbed the desired quantity of dyestufi.

5. A process for finishing a dyeing produced on wool with a dyestuffcontaining a chlorotriazine radical in a bath which is acid with aceticacid at the beginning of the dyeing operation, which process comprisesraising 8 the pH value of the bath above 6 by addition vofammonia whenthe fibers have absorbed the desired quantity of dyestufl.

6. A process for finishing a dyeing produced on wool with a dyestuficontaining a chloropropionyl radical in a bath which is acid with aceticacid at the beginning of the dyeing operation, which process comprisesraising the pH value of the bath above 6 by addition of ammonia when thefibers have absorbed the desired quantity of dyestufi.

7. A process for finishing a dyeing produced on wool with a dyestuficontaining a chlorotriazine radical in a bath which is acid with aceticacid at the beginning of the dyeing operation, which process comprisesraising the OH HOsS with a dyestuff containing a chloropropionyl radicalin produced on wool 4 a bath which is acid with acetic acid at thebeginning of the dyeing operation, which process comprises raising thepH value of the bath above 6 by addition of hexamethylene 'tetraminewhen the fibers have absorbed the desired quantity of dyestufi.

9. A process for finishing a dyeing produced on the wool part of amixture of wool and cellulose fibers in an acid bath with a dyestuflcontaining at least one mobile halogen atom, which process comprisesraising the pH-value of the bath above 6 when the wool fibers haveabsorbed the desired quantity of dyestufr' and then dyeing the cellulosefibers in the same bath with a substantive dyestuff.

10. A process for finishing a dyeing'produced on the wool part of amixture of wool and cellulose fiber-s with a dyestufi containing atleast one mobile chlorine atom in a bath which is acid with acetic acid,which process comprises raising the pH-value of the bath above 6 whenthe wool fibers have absorbed the desired quantity of dyestufi: and thendyeing the cellulose fibers in the same bath with a substantivedyestuff.

References Cited in the file of this patent UNITED STATES PATENTS Re.11,647 Schaefier Feb. 1, 1898 654,864 Wilson July 31, 1900 2,719,104Westerberg Sept. 27, 1955 2,723,262 Guasco Nov. 8,1955 2,773,871 Brasselet al Dec. 11, 1956 2,895,785 Alsberg et a1 July 21, 1959 2,900,218 GrayAug. 18, 1959 2,903,324 Hirsbrunner Sept. 8, 1959 2,914,531 Staeuble eta1 Nov. 24, 1959 2,940,812 Denyer et a1. June 14, 1960

1. A PROCESS FOR FINISHING A DYEING PRODUCED ON NITROGENOUS FIBERS IN ANACID BOTH WITH A DYESTUFF CONTAINING AT LEAST ONE MOBILE HALOGEN ATOM,WHICH COMPRISES RAISING THE PH VALUE OF THE BATH ABOVE 6 WHEN THE FIBERSHAVE ABSORBED THE DESIRED QUANTITY OF DYESTUFF.